1. Field of the Invention
This invention relates to marker pen devices of the type which contain volatile or unstable liquids in a sealed glass tube, which is broken to permit the liquid to be dispensed through a spring action mb valve.
2. Description of the Prior Art
Marker or paint type pens which contain volatile liquids are available in the prior art. Such pens typically include an impervious tube, sealed at one end, and capped at the other open end with a spring action valve. The valve is activated by depressing a rigid or porous marking or painting nib of well known type. These pens are available from a variety of manufacturers such as Flocon, Inc., J.P. Nissen Co., Ideal Stencil machine and Tape Co., and Aubex Corporation.
The prior art pens are typically constructed by filling the tube with a liquid, which could be a volatile or unstable liquid, and sealed at the open end by inserting a spring loaded nib valve, which fits tightly in the tube, and sealing the nib valve with a hood.
To use the pen, the hood is removed, the pen is inverted and the nib is depressed opening the spring loaded valve, allowing the liquid to flow through or around the nib and applied to the surface to be marked or painted.
While these pens may be suitable for many liquids, they are not satisfactory for sealing and dispensing very volatile or unstable liquids that cure or polymerize through the introduction of atmospheric water vapor as a catalyst for polymerization. These pens do not satisfactorily store or dispense liquids containing isocynates, such as polymeric diisocynate or hexamethylene diisocynate or cyanoacrylate adhesives.
One of the problem with the described prior art pens is that the valve construction may allow air and atmospheric water vapor to enter the pen, and cure the liquid or allow the liquid to evaporate from the pen during storage prior to initial use.
This sealing defect has restricted the use of these pens from liquids that are sensitive to moisture or are volatile. In effect, it is not practical to use these pens with the described liquids due to their very short shelf life.
In the pens of the invention the volatile liquids are stored in a sealed impervious glass tube, which may contain a metallic ball for mixing and breaking of the tube for dispensing the liquid through a spring loaded nib valve. Alternatively, the tube may be crushed by an external slide ring activator of the type shown in my prior U.S. Pat. Nos. DES. 413,730 and DES. 416,389.
The new pen structure provides consistent results, does not suffer from the disadvantages of the prior art, and provides many other advantages.